Effects of physical conditioning on cardiorespiratory function, body composition and serum lipids in relatively normal-weight and obese middle-aged women.

The primary purpose was to investigate the effects of a 12-week (4 day/week) physical conditioning program on cardiorespiratory function, body composition, and serum lipids (cholesterol and triglyceride concentration) in sedentary, middle-age women. A secondary purpose was to clarify the influence of excessive body fatness on the conditioning response. Forty-two 29 to 47-year-old premenopausal women volunteered; four were excluded and two dropped out, leaving 36 who completed the study, ie, 23 obese (O) (greater than 30 per cent fatness, mean = 38 per cent) and 13 lean to normal (N) (less than 30 per cent body fatness, mean = 25 per cent). The conditioning program included a 10-minute warm-up, 15 to 25 minutes of walking-jogging at an individually prescribed training heart rate corresponding to 75 per cent of maximal oxygen intake (VO2max) and a five-minute recovery period. Heart rate and systolic blood pressure at a given submaximal work load decreased in both N and O. VO2max increased (P less than 0.001 in both groups. The average increase in O was 15.0 per cent and 18.9 per cent and in N 12.6 per cent and 12.7 per cent when VO2max was expressed inlitre .min-1 and cm3.kg-1.min-1 respectively. HRmax remained unchanged in N, but decreased slightly (P less than 0.01) in O. Body weight remained essentially unchanged in N, yet decreased (P less than 0.001) in O. The sum of ten skinfolds decreased significantly (P less than 0.001) in both groups, but with a greater reduction in O. Fatness decreased slightly in N (P less than 0.05) and more in O (P less than 0.001) while fat-free weight remained unchanged in both groups. The conditioning program had no effect on serum lipids in either group. Thus, a physical conditioning program of moderate intensity affected obese and leaner women in a similar fashion.